The present invention relates generally to valves and more particularly to a device for creating a variable fluid passage which will closely approximate the shape of a venturi tube. In the art of fluid flow control, the various devices, such as valves and orifices, which have been utilized to control the flow of fluid, have generally imposed a significant pressure drop on the system. Attempts have been made in the prior art to overcome these problems. For example, in U.S. Pat. No. 2,434,835 to Colley a variable fluid passage is shown wherein a flexible tubular lining is contained within a conduit having outer and inner sections. A plurality of cables are affixed to the outer conduit member and to the flexible tubular lining at the center thereof. Rotation of the outer conduit with respect to the inner conduit has the effect of creating a venturi-shaped passage with a tightened throat and a reduced diameter along substantially the entire length of the passage. U.S. Pat. No. 2,560,634 to Colley shows another variable throat venturi in which a flexible tubular member is compressed and expanded by means of a plurality of motors driving a plurality of studs into and out of the walls of the tubular member. Additionally, nozzles are known which include variable restrictions. For example, U.S. Pat. No. 2,915,078 to Ochs, Jr., shows a variable nozzle restriction wherein a flexible conduit is compressed along its entire length by means of fluid pressure to vary the nozzle restriction; and U.S. Pat. No. 2,934,892 to Hurlbert, et al., teaches the use of a variable propulsion nozzle which utilizes a plurality of straps which are twisted in a spiraling relationship to expand or contract the area of the nozzle. These prior solutions have failed to completely solve the pressure drop problem and additionally have been rather complex, and therefore, costly in nature.